Automatic tire stitching machine



8 Sheets-Sheet 1 July 23, 1946. cl s. MccHEsN I AUTOMATIC TIRE STITCHING ACHINE Original Filed Oct. 3; 1942 INVENT'OR r1 ER 5, Mo CHESNEV.

July 23, 194

C. S. MPCHE SNEY AUTOMATIC TIRE STITCHING MACHINE Original Filed Oct. 3, 1942 j 8 Sheets-Sheet 2 IN VEN TOR.

ATTORNEY July 23, 194 6. c. s. MGCHESINEY 7 2,404,449. I

'AUTOMATIC TIRE STITCHING MACHINE Original Filed Oct. 3, 1942 8 Sheets-Sheet 3 1 4 INVENTOR. I

Cu r1. I51? I15 1% C'HESNEK "w ATTORNEY July 23, 1946. c. $(M CHESNEY AUTOMATIC TIRE STITCHING MACHINE Original Filed Oct. 5, 1942 8 Sheets-Sheet 4' /II!////////////////////////III/I47 l I I INVEN TOR. CUVL E4? 5. Mt. Chas/ E).

A TTORNEV July 23, 1946.

C. S. M CHESNEY AUTOMATIC TIRE STITCHING MACHINE Original Filed Oct. 3, 1942 a Sheets-Sheet 5 E v 3% M M EH 0 W w w A M. rv. a

July 23, 1946. I

C. S. M CEIESNEY v AU'roMATic TIRE STITGHING MACHINE Original Filed Oct. 5, 1942 8 Sheets-Sheet 6 July 23, 1946.

c. s. MCCHESNEY AUTOMATIC TIRE STITCHINQ MACHINE Original Filed Oct. 3, 1942 8 Sheets-Sheet 7 IN VEN TOR.

A TTOR/V E Y July 23, 1946. c. s. M CHESNEY 7 2,404,449

AUTOMATIC TIRE STITCHING MACHINE Original Filed Oct. 3, 1942 a sheets-sheets ATTORNEY Patented July 23, 1946 AUTOMATIC TIRE STITCHING MACHINE Cuyler S. McChesney, Kenmore, N. Y., assignor to Dunlop Tire and Rubber Corporation, Buffalo, N. Y., a corporation of New York Original application October 3, 1942, Serial No.

, 460,705, now Patent.No. 2,394,464, dated February 5, 1946. Divided and this application November 18, 1944, Serial No. 564,159

My present invention relates to an automatic tire tread stitching machine, that is, to one in which the tread of a tire after being placed in position on the underlying fabrics is pressed or rolled by disks which pass from a mid line of the tread outwardly to the edges from whence they are removed from the tread and returned to their original position.

The present application is a division of my copending application Serial No. 460,705, filed October 3, 1942, for a Tire building machine, now Patent No. 2,394,464, dated February 5, 1946.

In building a tire carcass on a flat drum layers of bias cut fabric are wrapped on said drum with the threads of one layer at an angle to those of the underlying and. overlying fabrics, thereafter breaker and chafer strips are applied and, finally, a tread strip is wrapped on the assembled fabrics midway between the ends of the drum. To unite the rubber of the tread strip to the fabric on which it is wrapped it is pressed by a pair of circular disks which bear against the outer surface of the tread strip and as the drum is rotated the disks rotate circumferentially of the drum while they are gradually separated to the edges of the tread strip. After the tread is thus united with the underlying fabrics the drum is collapsed and the carcass shaped in a suitable mold.

In the tire building machine of my previously mentioned Patent.No. 2,394,464, the drum is rotated and the various tire elements brought into position thereon in sequence timed by a timer rotated by the drum rotating mechanism and also by a series of manually operated control levers.

While my present invention is particularly suited to the machine shown in said co-pending application, it is applicable to any tire forming machine in which a tread is to be stitched to the underlying fabric.

In my present invention the stitching is automatic so that it is only necessary for the operator to press a control lever whereupon the rotating disks are brought under pressure against the outer surface of the tire tread strip while the drum is rotating so as to cause the disks to rotate.

15 Claims. (Cl. 15410) the invention is applied and a and control mechanism.

' Fig. 2 is a'plan view of the mechanism shown in Fig. 1, showing the position of the stitching mechanism relative to the drum. I

Fig-3 is a vertical section taken on line 33 of Fig. 4 through the driving and control mechanism for thedrum and showing the control devices for the stitcher mechanism.

part of the driving Fig. 4 is a section through the driving and control mechanism taken on line 44 of Fig. 3.

Fig. 5 is a vertical section of the driving and control mechanism taken on line 55 of Fig. 3. Fig. 6 is a longitudinal sectional view of the stitcher and driving mechanism.

Fig. 7 is a side view on a larger scale of the control mechanism for the stitcher.

Figs. 8 and'9' are respectively sectional views of the stitcher control mechanism taken on lines 88 and 9-9 of Fig. '7. t

Fig. 10 is a wiring diagram showing the electric circuit for the control of the various elements.

In the tire building machine shown in the accompanying drawings and embodying a preferred form of the invention, the mechanism is mounted on a base II having a housing I2 for the'drum driving and control mechanisms, said base hav ing an extension I3. A forming drum- I4 is mounted over the extension I3 on a hollow rotating shaft I5 and an internal shaft I6 which project from the housing I2 and are driven by a motor I1, Fig. 3, within the housing I2, through a pulley I8 on the motor to a driving belt I9 and. a pulley 20 on the inner shaft I6.

The shaft I5 is supported by the shaft I6, one end of which is journaled in roller bearing 2 I, and by the roller bearing 22. The inner and outer shafts I5 and I 6 may be stopped by means of brakes 23 and 24 respectively for the purpose of expanding or collapsing the drum. The various 21 and a, shaft 28. p

The various fabrics of a tire carcass are built up on the drum I4 and the tread is then wrapped about the drum and stitched in position thereon by the stitcher mechanism of the present invention.

This. stitcher mechanism comprises a pair of rollers or disks 29 and 30 having hubs 3| and 32 slidably mounted on a hollow supporting shaft '33 which is mounted at its ends in a suitable bracket34, Fig. 6. The bracket 34 com prises an arm 35keyed onto a shaft 36 journalled on a standard 31 and has a pair. of branches I to the cylinder 46;

38 and 39 extending parallel with the surface of the drum and then turned at right angles to form the supporting ends or heads 40 and M for the 7 Within the housing I2 an arm 44 is rigidly I end is connected, as shown in Figs. 4 and 5, to

the end of a piston stem 45 extending into. a.v

pneumatically operated cylinder 46- which. is

pivoted to a rib 41 in the housing I2.

When actuating fluid under pressure is admitted to the left end of thepiston as shown in Fig. 4, or at the right-hand as: shown inFi'g: 5, forcing the piston rod 45 out of the cylinder, it rocks the shaft 36 clockwise as viewed in Fig. 5, and thus brings the edges of the stitcher'disks 29 and 30 into contact with the edge of the tread.

Contact with the tread. causes: the stitcher. disks to rotate on the shafti33 with a pressure that is' controlledby't-he pressure-fluid admitted The disks Z9 and-30 are-movable longitudinally on. theshaft 33 and in order to enable them tofollow the contour of the tread the arm 35 of. the. bracket 34-: is' made in. two parts, a lower part 48- being keyed: directly to the shaft 36; and an upper'part 49 carrying the arms 33 and 39, being secured to a pivot pin' 50- by means of a screw 51, or other uitable means; which: extends into. asuitablerecess in I the lower part 48 and is:.rotatably locked: therein by a pin 52 engaging a recess Win the pivot pin. 50. In' this way the upper branched: part is secured to the lower: supportingi part 48 to per- I the forming drum as they are broughtginto contact with the latter. They are then. caused to separateto a. predetermined distance: while ro- I tating in contact with the surface of the; tread j and upon further rotation arebrought together after. they havebeen tiltedt out: of contact. with the tread.

The disk s' 29. and 30 are moved longitudinally onthe shaft 33 by means. of a screw shaft: 54

extending lengthwise within'rthe hollow shaft. 33 and rotatablyv mounted in. bearings. -5 and. 56

I in the heads 38 and 38'of the bracket. Thescrew I shaft 54 has left-hand and right-hand screw threads 51' and 58 extending fromzitsmid point.

On the screw threads '51 and 58 arermounted a pair of nuts 59 and 60 which. are held from rotationby means of projections BI and 62 which extend. through a longitudinal. slot 53,. Fig. 6;

1 in the shaft 33' and enter inner annular: grooves 64 and 65 of the hubs 3 I. and 32..

When the shaft 54 is rotated in one direction 7 the nuts. 59 and 60 are pushed inopposite directions' from themid point of the screw and the j projections BI and 62' will. carry therespective stitcher disks 29 and 30'while permitting these disks to rotate. The screw shaft 54 extends through the end of. the bracket 38 and carries aspro'cket EB k-eyed onto, the projecting. end of the" screwshaft and connected by means of a chain; 6.1, Fig... 6, to a sprocket 68-. keyed to the end of a shaft 69- mounted in a suitable. bearj ingv 102m: 'anear H on.thebracket branch 38-. I

The. sprockets 66, 68, and the chain 6 a 4 covered by a suitable cover I2. The opposite end of the shaft 69 is mounted in a suitable bearing 73 on the part 4 9 of the bracket 34. The shaft 69 is connected through a train of gears 14,;15-and I5 toa drive shaft I1 journalled in andextending'tlirough.the rock shaft 36 into the housing I2. The shaft 1! is driven from an individual motor I8 within the housing l2, Fig. 7, through a belt I9 connecting the pulley 80 of the motor to a pulley 8| mounted on the projecting end ofthe shaft 11. I

The shaft 'II-also drives a limiting device for limiting the travel of the stitcher disks 29 and 30. This limiting device comprises a screw threaded shaft" 81 mounted in bearings 88 and 89 suspended. at spaced intervals from a crossbeam. 9.8. The shaft 81 is driven from the shaft 11 through a pinion'9l keyed to the shaft 1'! and meshing with a gear 92 keyed or pinned on the screw shaft 81. The shaft 8'! is thereby rotated in fixed relation to the. shaft Hz.

A nut 93is v threaded on: the shaft Wand-is provided with .agroove Min us-upper edge which receives a guide'bar' 95-secured;to the'lower sur faceof the cross-beam to prevent the nuttfrom rotating. As the shaftllfl' is: rotated iii-one. direc? tion or the other the nut: 93' moves infa= corresponding direction lengthwise of theshaft 8:1.

The nut. 93- isprovided with a sidewise. extending cam 96', as shown particularly in Figs. '7 and 8. which engages and lifts a lever arm 9! of a: limiting switch 98 or alever 990i alimit switch IIIII'; When the motor 18 is to be started the. nut 93-wil1 be below one of the levers 91'or99; depending upon the direction in which. the disks 29* and .38 and,v correspondingly; the shaft. 8:1,- isto. rotate.

As the disks 29 and.30 and shaftslrotate, the nut 93 is threaded forwardly on the. shaft 8'Tuntil it contacts with, andlifts, the other of the-levers 91 and 99,.whereupon'. the corresponding switch acts .to reverse the motor i8 and; accordingly; the nut'93 threads its way backtoitsroriginal position and, lifting the corresponding switchlever, opens the' circuit contact. to the motor l8 which; thereupon stops;

In order to prevent the shaft 81' from overriding its position, a suitable resistance to rotation maybe provided bymeans of abrake drum IIlI keyed on the shaft 81' and engaged by a flexible brake band I02 secured atone end-on the cross beam 9fland at the other end to a rod Illmwhi'ch is resiliently pressed upwardly by means of "a spring I04 confined between' t'he beam 9i] and'retaining nut I051 The switches 98 and I00 are mounted onblocks I06 and Hi! Which are slidably mounted on an upwardly projecting web of the beam and may I be secured in any desired position by means of a set screw I09. The switches may thereby be adjusted to provide any desired interval between the starting andistoppi'ng of the motor 18" and the stitching disks 29 and 30.

The electric circuits for controlling the above mechanism are shown inthe wiring diagram of Fig. 10. In this diagram current is supplied from the mains III) and' III. At the time that the tread stitcher operates the drum I4'rotates at a high speed. To start the rotation of the drum motor II a switch I I2 is'closed thereby closing a circuit through a wire 3 to a branchwire' H4 and the high speed starting mechanism for the motor II. This starts and rotates the drum I4 at a high speed.

The switch H2 is connected to a switch 5 in a branch circuit H6 in such manner that the 7 switch I I5 is normally closed when the switch The energizing of the electromagnet III also closes a switch II 9 in a shunt circuit I29 thus maintaining 'a circuit through the electromagnet 'I I! after theswitch I I5 is opened.

The energizing of the electromagnet II'I also closes a switch I2I in a branch circuit I22 leading from the branch II 3 through an electromagnet I23, which controls a valve I24 for the admission of pressure fluid to the cylinder 46 entering at the left end of the cylinder as viewed in Fig. 4. This rotates the disk carrying bracket 34 to bring the disks 29 and 30 against the surface of the tread with a pressure governed by the pressure fluid admitted to the cylinder 45. time it closes a pressure actuated switch I25 in a branch circuit I29 leading from the main III) through the windings or control mechanisms of the stitcher motor I8 setting this motor in operation.

The direction of the motor is controlled by a branch circuit I21 leading from the branch circuit I22 through a solenoid I28 which controls a reversing and starting mechanism I 29. Current is supplied to the starting mechanism initially through the branch circuit I28 and the pressure switch I25 and a connecting shunt I39. The shunt I 30; connects with a branch circuit I3I which is closed by an in limit switch I99. The current is supplied initially through the circuits I26, I30 and HI until themotor is started and the disks separate whereupon the in limit switch I88 closes and current then flows directly from the main III! to the control mechanism I29.

The control mechanism I29 comprises a pair of branch circuits I32 and I33 connected to each other through a reversing circuit I34 and connected alternatively to the circuit I3I by switches I35 and I36 operated by the solenoid I28 in such a manner that one is closed when the other is opened.

The circuits I32 and I33 are connected to a return circuit I31 leading to the main I II by means of a pair of switches I38 and I39 which are also controlled by the solenoid I28 and operate in the reverse of the switches I35 and I35.

It will be apparent, therefore, that when the solenoid I28 is energized current will flow through one of the switches as, for example, I35, thence in one direction through the control circuit I34 and through the switch I39 to the branch I31 and main I I I. This continues until the out limit switch 98 is opened whereupon the circuit through the electromagnet II! is opened, opening both of the switches H9 and I2I. through the electromagnet I23of the fluid control valve I24, reversing the position of this valve, whereupon the bracket 34 falls away or is withdrawn from the drum I'4.

Also the circuit is broken through the solenoid I28 opening those sWitches in the control mechanism I29 that were closed and closing those that were open and thus reversing the current through the control coil I34. Thereupon the direction of rotation of the motor I8 is reversed, reversing the rotation of the shaft 81 and the screw shaft 54. The disks ar'e, therefore, returned to their original central position at the same time the cam 96 At the same i This breaks the circuit 4 6 is moved back until it opensthe in limit switch I90.

Inasmuch as the switch I25 has been opened by the release of pressure on the bracket 34 the opening of the in limit switch I00 breaks the circuit through the motor I8 and the control device I29, thereupon the motor stops as the disks reach their 7 original position as indicated in broken lines in Fig. 6.

It will be understood that the above wiring is purely diagrammatic and that other wiring arrangements might be made.

Through the above apparatus the tread is given a uniform predetermined stitching which may be adjusted by adjustment of the position of the switch 98 for any width of tread. The stitching continues uniformly from the mid point of the tread to the outer limit for which the mechanism is setrand upon reaching this predetermin'ed'outer limit is withdrawn and returned to its original position without requiring attention by the operator. It is only necessary for the operator to close the switch H2, or operate a mechanism for closing it as described in my previously mentioned Patent No. 2,394,464, whereupon the stitching of the tread will be accomplished without such variation as might occur if the operation were controlled by the operator. The result is that the stitching for each tread is uniform without danger of falling short of the edge of the tread or overrunning this edge.

What I claim is:

1. -A tread stitcher for stitching tread on a tire carcass on a rotatable forming drum which comprises a shaft, a pair of stitching disks rotatably and slidably mounted on said shaft, means to move said shaft to bring the peripheries of said disks against the tread on said forming drum, means to slide said disks toward and from each other on said shaft, control means comprising an electric circuit having a pair of cam operated. switches to control the direction and extent of movement of said disks, a cam for operating said switches and means to move said cam to and from said switches in proportion to the movement of said disks.

2. A tread stitcher for stitching tread on a tire,

carcass on a rotatable forming drum which comprises a shaft, a pair of stitching disks rotatably and slidably mounted on said shaft, means to move said shaft to bring the peripheries of said disks against the tread on said forming drum,

means to slide said disks toward and from each other on said shaft, control means comprising an electric circuit having a pair of cam operated carcass on' a rotatable forming drum which comprises a shaft, a pair of stitching disks rotatably and slidably mounted on said shaft, fluid actuated means to move said shaft and disks toward and from the forming drum to bring the peripheries of said disks against said tread. means to slide said disks toward and from each other on said shaft. control means comprising an electric circuit having a pair of cam operated switches to control the direction and extent of movement of said disks and the admission of fluid to said fluid actuated means, a cam for operating said switches and; means, to move said cam to and from said switches in proportion to the movement of said disks.

4. A tread stitcher for stitching tread on a tire carcass on, av rotatable forming drum which comprises a bracket having a stem and a pair of arms, a support for said bracket to permit said bracket to rock to andfrom said drum and about the axis of said stem, a shaft mounted between thearms of'said bracket, a pair of stitching disks rotatably'and slidably mounted on said shaft, means to slide said disksto and from each other on said shaft, control means comprising an elecof rotation of said drum, a pair of disks rotatable on said shaft and slidable thereon to and from a position substantially midway of said tread, a shaft threaded oppositely from a mid point, a pair: of nuts one for each disk threaded on. said oppositely threaded parts of said shaft and movable-toward or from each other as said shaft is rotated forwardlyor in reverse, said disks rotatably engaging their respective nuts, an electric circuit having a pair of spaced cam operated switches one, to limit the outward movement-and the other the inward movement of said disks, a screw driven synohronouslywith said shaft and a cam threaded on said screw to operate said switches alternatively in its movement on said SCI'GW.

6. Atread stitcher for stitching tread on, a tire carcass on a rotatable forming drum which com an. electric circuit comprising means to start and reverse therrotation of said shaft and the tilting ofv said bracket toward and from said drum and having a pair of spaced cam operated switches to start and reverse therotation of said shaft, a screw driven synchronously with said shaft, and a cam threaded on said screw to engagesaid switches alternatively in itsmovement on said screw.

7. A tread stitcher for stitching tread on a tire carcass on a rotatable forming drum which comprises a bracket pivoted to swing toward and from saidwdrurn andhaving a pair of arms, a rotatable screw threaded shaft mounted on and between said arms and threaded oppositely from the mid point of said drum, a supporting shaft, a pair of disks rotatable and slidable on said supporting shaft, threaded shaft each rotatably engaged by one of said disks, anelectric circuit comprising means to drive said threaded shaft forwardly and in reverse and havinga pair of spaced startin and reversing switches, a cam movable to operate said switches alternatively, av screw engaging said cam,

'8, and gearing connecting said screw-and said rotate able shaft to rotate infixed relation.

8. A tread stitcher for stitching tread, orra tire carcass on a rotatable forming drumrwhichcom prises a bracket pivoted to swing toward and'from said drum and having a pair of arms, a rotatable screw threaded shaft mounted on and between said arms and threaded oppositely from the; mid point of said drum, a supporting shaft, a pair, of disks rotatable and slidable on said supporting shaft, nuts threaded, on, said, rotatable screwthreaded shaft each rotatably engaged by'oneof said disks, an electric circuit comprising means to drive said threadedshaft forwardly and in reverse and having a pair of spaced starting; and

reversing switches, a cam movable to operate said switches alternatively,,a screw engaging said cam, gearing connecting'said screw and said rotatable shaft to rotate in fixed relation, fluid" operated means to tilt said bracket toward and from said drum and means in said circuit to control the ad;- mission of fluid to and its exhaust from said fluid operated means.

9. In a tire building, machine a rotatable; drum;

' a pivoted bracket having a hollowshaft parallel to the axis of said drum and having a longitudinal slot, a pair of disks rotatable and slidable on said shaft, means to tilt saidbracket tobring the edges of said disks into engagement with the sur-' face of said drum, a rotatable screw within said shaft and threaded oppositely from the central plane of said drum, nuts, one for: each disk; threaded on said screw on opposite sides of said plane and projecting through the slot of said shaft to said respective disks to move said diskstio and from each other'by the rotation of. said screw relative to said nuts andmeans to limit rotation nuts threaded on said rotatable screw of said shaft and separation of said disks, said means comprising a screw rotatablein definite relation to said first screw, electric. circuits comprising adjustably fixed contacts, and a nut threaded on said second screwin position to close and open said contacts.

10. In a tire building machine a rotatable forming drum, a pair of stitching'disks freely'rotatable on an axis parallel to that of said drum, rotatable means to separate and return said disks, a screw rotating in fixed relation to said rotating separating means, a nut threaded on said. screw'and held against rotation to move in one direction or the other as said screw is rotated in one direction or the other, fixed switches in the path of said nut to be closed by contact therewith and electric circuits closed by said respective switches to reverse and to stop said disk moving means.

11. In a tire building .machine, a rotatable forming drum, a pair of stitching disks freely rotatable on an axis substantially parallel to that of said drum, rotatable means to separate and return said disks, a movable switch actuating member, means to move said member back and forth in fixed relation to the positions of said disks and a circuit controlling the movement'of said disks and comprising spaced switches actuated by said switch actuating member tostop and start the movement of said disks.

12; A- tread stitcher for stitching elements of a tire carcass on a rotatable forming drum which comprises a shaft, a pair of stitching disks rotatably and slidably mounted on said shaft, means to move said shaft to bring the peripheries of said disks against the carcass on said forming drum, means to slide-saiddisks toward andfrom eachother on said shaft, and controlmeans-comprising: an: electric, circuit, anv electromagnet; in

said circuit to control the movement of said shaft; toward and from said drum, a branch circuit to control the disk sliding means, a pressure switch in said branch circuit actuated by pressure of said disk against said drum to energize the disk sliding means, means to move said disks from each other, an out limit switch to reverse said disk sliding means and to reverse the electromagnet controlling the movement of said shaft toward said drum and an in limit switch to stop the disk sliding means. 7

13. A tread stitcher for stitching elements on a tire carcass on a rotatable forming drum which comprises a shaft substantially parallel to the axis of rotation of said drum, a pair of disks rotatable on said shaft and slidable thereon to and from a position substantially midway of said tread, a shaft threaded oppositely from a mid oint, a pair of nuts one for each disk threaded on said oppositely threaded parts of said shaft and movable toward or from each other as said. shaft is rotated forwardly or in reverse, said disks rotatably. engaging their respective nuts, an electric circuit having means actuated thereby to advance said disk carrying shaft toward said drum to press said disks edgewise against the peripheral surface of said drum, a pressure actuated switch actuated on the pressing of said disks against said peripheral surface to actutae said threaded shaft and a pair of cam operated switches, one to limit the outward movement and the other the inward movement of said disks, a screw driven synchronously with said shaft and a cam threaded on said screw to operate said switches alternatively in its movement of said screw.

14. A tread stitcher for stitching tire elements on arotating forming drum which comprises'a pair of stitching disks, means to advance said disks into edgewise pressure engagement with the tire elements on said drum and reversely away from said drum, means to move said disks from mid position outwardly toward the opposite ends of said drum and reversely, a control cam and means to move said cam in onedirection with,

and in proportion to, the outward movement of said disks and reversely, and an electric control circuit comprising a starting switch, means to control said disk advancing means on'*actuation of said starting switch, a pressure switch actuated on pressure engagement of said disks against said drum and controlling the outward movement of said disks, an out limit switch actuated by said cam to reverse said disk advancing means and said disk moving means and an in limit switch actuated by said cam to stop said reverse movement of said disk moving means. 7

15. The tread stitcher of claim 14 and a circuit controlled by said starting switch to control the rotation of said drum.

CU'YLER S, McCHESNEY. 

